Screening Colonoscopy

Colonoscopy is a procedure during which a long flexible tube with camera is inserted through the anus to inspect the colon, rectum and sometimes the ileum (the last part of small intestine). It is an outpatient procedure typically done under sedation in an endoscopy suite of hospital or outpatient surgery center. Colonoscopy may be done as a diagnostic test or a screening test. It is a diagnostic test when you have lower intestinal tract symptoms such as blood in stool, change in bowel habit or anemia, and the colonoscopy is used to obtain direct visualization and possible biopsy to confirm a diagnosis. Colonoscopy is done as screening (for colorectal cancer) when you do not have symptoms, and the main purpose is to detect and possibly remove polyps in the colon and rectum, thus preventing them from turning into cancer. The colonoscopy is performed in the same manner whether it is done as diagnostic or screening. The difference is how your insurance plan would cover the cost of the procedure (this translates to how much you have to pay out-of-pocket).

Current recommendations for screening colonoscopy

You should have your first screening colonoscopy by age 45 if you are at average risk for colorectal cancer. You may need screening earlier and at more frequent intervals if you have the following conditions that put you at higher risk:

  • Family history of colorectal cancer (especially in parents or siblings), multiple cancers in the family

  • Certain genetic syndrome such as Lynch syndrome and Familial Adenomatous Polyposis (FAP)

  • Personal history of colorectal polyps

  • Inflammatory bowel disese

  • Personal history of other cancer such as breast, uterine or ovarian cancer.

Alternatives to screening colonoscopy

Colonoscopy is the "gold standard" and is the preferred method for screening. The screening is covered by insurance as a preventive health measures, with no out-of-pocket cost in most cases when done at the proper time interval as recommended. Sometimes, people are not able to get a screening colonoscopy for reasons such as lack of insurance, unable to take time off, or unwillingness to undergo bowel prep, etc. Some alternative screening tests are:

  • Stool DNA test (Cologuard® )

  • Fecal immunochemical test (FIT)

  • Fecal occult blood test (FOBT)

  • CT colonography - needs bowel prep like colonoscopy, not always covered by insurance

These test may not be sensitive enough for small polyps, and if the stool-based test results are positive (suggesting blood and/or abnormal cells in stool), or CT colonography shows suspicious findings, you will need a colonoscopy for confirmation and potential treatment.

Helpful links:


*American Cancer Society

**American Society for Gastrointestinal Endoscopy

***American Society of Colon and Rectal Surgeons